Contacts not syncing with gmail and merge contacts option not present in contacts menu

Hello, I'm new to the Android environment and have come across a few issues. I'll be posting them in different threads so apologies beforehand.
I tried syncing up contacts on an s3 and s4. I activated syncing in Gmail and s elected the items to sync, including contacts. It showed it had synced. Then I went to merge contacts and the option is not there in the menu. Contacts in Gmail is also blank. The phones are unlocked, rooted and being used abroad. I repeated the process on a galaxy grand neo bought here and the merge contacts option is there and about a fifth of the contacts did sync to Gmail but clearly that's not great either. What am I doing wrong?